Magnetic tape cartridge having self docking leader block

Abstract

The magnetic tape cartridge having a self docking leader block makes use of guide slots formed in the interior surface of the top and bottom plates of the cartridge housing, juxtaposed to the leader block opening in the housing, to mate with corresponding projections on the leader block. The guide slots are open at one end to capture the projections on the leader block and shaped to precisely guide the leader block along a predefined path into the opening.

We claim: 
     
       1. A magnetic tape cartridge comprising: a substantially rectangular housing, including a top plate and a bottom plate, having an opening in one corner thereof, for enclosing a single reel of magnetic tape;   a leader block for said magnetic tape, wherein said leader block has a top, and a bottom, and includes an aperture in a first side for receiving a first end of said magnetic tape, and first and second docking pin located on said top and bottom, respectively, of said leader block, proximate said first side and adapted to guide said leader block into said opening;   first slot inscribed in an interior surface of said top plate of said housing, proximate said opening and having a first end open to said opening in said housing to receive said first docking pin on said leader block to guide said leader block into said opening; and   second slot inscribed in an interior surface of said bottom plate of said housing, proximate said opening and having a first end open to said opening in said housing to receive said second docking pin on said leader block to guide said leader block means into said opening.   
     
     
       2. The magnetic tape cartridge of claim 1 wherein said aperture is located along a centerline of said first side to enable a tape threading mechanism leader block threading pin to pull said leader block in a straight line with said magnetic tape. 
     
     
       3. The magnetic tape cartridge of claim 1, further comprising: a leader block latch member to prevent the withdrawal of said leader block from said magnetic tape cartridge; and   said leader block further comprising means adapted to receive said latch member when said leader block is withdrawn into said magnetic tape cartridge.   
     
     
       4. The magnetic tape cartridge of claim 3, wherein said receiving means comprises a slot on a second side of said leader block adapted to mate with a corresponding projection on said latch member. 
     
     
       5. A magnetic tape cartridge, comprising: a substantially rectangular housing including a top plate and a bottom plate, which housing has an opening in one corner thereof and is adapted to enclose a single reel of magnetic tape rotatably mounted within said housing and including a leader block attached to one end of said magnetic tape;   latch arm means located within said housing proximate said opening, pivotally connected to said housing and having a first end operable into a first position to block the movement of said leader block through said opening in said housing; and   first and second leader block guide means located on an interior surface of said top plate and said bottom plate of said housing, respectively, proximate said opening an mating with corresponding projections on said leader block to guide said leader block into said opening.   
     
     
       6. The magnetic tape cartridge of claim 5 wherein said first leader block guide means comprises: a slot inscribed in said interior surface of at least said top or bottom plate of said housing and having a first end open to said opening in said housing to receive a corresponding projection on said leader block.   
     
     
       7. The magnetic tape cartridge of claim 6 wherein said slot has a second end closed to stop the movement of said leader block into said housing by engaging said projection on said leader block. 
     
     
       8. The magnetic tape cartridge of claim 5 further comprising: an aperture in said housing adapted to receive a leader block latch release pin located on a tape drive, wherein said aperture is located proximate to said opening to enable said leader block latch release pin, as said magnetic tape cartridge is loaded into said tape drive, to rotate said latch arm means to a second position wherein said latch arm means fails to block the movement of said leader block through said opening in said magnetic tape cartridge.   
     
     
       9. The magnetic tape cartridge of claim 8 wherein said first leader block guide means comprises: a slot inscribed in said interior surface of said top plate of said housing, having a first end open to said opening in said housing to receive a corresponding projection on said leader block and shaped to guide said leader block around said aperture.   
     
     
       10. The magnetic tape cartridge of claim 8 wherein said second leader block guide means comprises: a slot inscribed in said interior surface of said bottom plate of said housing, having a first end open to said opening in said housing to receive a corresponding projection on said leader block and shaped to guide said leader block around said aperture.   
     
     
       11. The magnetic tape cartridge of claim 5 wherein said latch arm means is flexible in a direction coplanar to said single reel to enable said leader block to be inserted into said opening in said magnetic tape cartridge when said latch arm means is in said first position. 
     
     
       12. The magnetic tape cartridge of claim 5 wherein said latch arm means includes a projection adapted to engage a feature on said leader block to block the movement of said leader block through said opening in said housing. 
     
     
       13. A magnetic tape cartridge, comprising: a single reel of magnetic tape;   a leader block attached to one end of said magnetic tape and having top and bottom surfaces, each having a projection located thereon;   a substantially rectangular housing including a top plate and a bottom plate, which housing has an opening in one corner thereof and is adapted to enclose said single reel of magnetic tape rotatably mounted within said housing;   first slot inscribed in an interior surface of said top plate of said housing, proximate said opening and having a first end open to said opening in said housing to receive said projection located on said top surface of said leader block to guide said leader block into said opening; and   second slot inscribed in an interior surface of said bottom plate of said housing, proximate said opening and having a first end open to said opening in said housing to receive said projection located on said bottom surface of said leader block to guide said leader block into said opening.   
     
     
       14. The magnetic tape cartridge of claim 13 wherein said first leader block guide means slot has a second end closed to stop the movement of said leader block into said housing by engaging said first projection on said leader block means. 
     
     
       15. The magnetic tape cartridge of claim 13 wherein said second leader block guide means slot has a second end closed to stop the movement of said leader block into said housing by engaging said second projection on said leader block means. 
     
     
       16. The magnetic tape cartridge of claim 13 wherein said magnetic tape cartridge further comprises: latch arm means located within said housing proximate said opening, pivotally connected to said housing and having a first end operable into a first position to block the movement of said leader block through said opening in said housing.   
     
     
       17. The magnetic tape cartridge of claim 16 further comprising: an aperture in said housing adapted to receive a leader block latch release pin located on a tape drive, wherein said aperture is located proximate to said opening to enable said leader block latch release pin, as said magnetic tape cartridge is loaded into said tape drive, to rotate said latch arm means to a second position wherein said latch arm means fails to block the movement of said leader block through said opening in said magnetic tape cartridge.   
     
     
       18. The magnetic tape cartridge of claim 16 wherein said latch arm means is flexible in a direction coplanar to said single reel to enable said leader block to be inserted into said opening in said magnetic tape cartridge when said latch arm means is in said first position. 
     
     
       19. The magnetic tape cartridge of claim 16 wherein said latch arm means includes a projection adapted to engage a feature on said leader block to block the movement of said leader block through said opening in said housing.